A programme to keep Europe flying safely the next time a volcanic ash cloud affects the continent's airspace is forging ahead, with trials for an airborne warning device just successfully completed near the volcanicly active Mount Etna in Sicily.
Icelandic volcanologists have reminded the industry that an eruption by Mount Katla, potentially ten times more powerful than the eruption by Mount Eyjafjallajökull that grounded European aviation in April 2010, is overdue and could occur at any time.
Speaking at a briefing in Sicily earlier this week, atmospheric scientist Dr Fred Prata, a key member of the ongoing airborne ash sensor trials team, said if Europe's aviation decision makers had known in April 2010 what is understood now, some 98% of the grounded flights could have operated safely, despite the presence of atmospheric volcanic ash. Prata said the next Katla eruption is "a case of when, not if", and if European commercial aviation has the confidence, by then, to deploy its new-found experience and knowledge, flying will be able to continue safely in much of the ash-affected airspace.
Prata is a senior scientist at the Norwegian Institute for Air Research (NILU), where he has been working for years in the sciences of earth observation and climate research. He is also technical director of Nicarnica Aviation, a NILU spin-off that is now working with EasyJet developing and testing an aircraft-mounted ash sensor called AVOID (airborne volcanic object imaging detector). It works passively in the infrared spectrum, providing a display for pilots to enable them to see the lateral and vertical location of airborne ash concentrations so they can alter course to fly around them. At 20,000ft (6,100m) altitude ash can be "seen" 100km away. The system can also take measurements of airborne ash to determine its concentration, thus confirming whether the levels are safe for aviation.
EasyJet's head of engineering, Ian Davies, is working with Prata to prepare for mounting the system on the carrier's aircraft, hopefully, he said, by the middle of 2012. He said the ash deployment information provided in the flight deck will not, at first anyway, be integrated with aircraft systems or avionics, so winning approval from the European Aviation Safety Agency will be relatively simple - only a supplemental type certificate is necessary.
Prata makes clear that AVOID is just one part of a multi-layered, comprehensive system which the world uses to predict, detect and measure the location of ash following a volcanic eruption anywhere in the world. At NILU he has been researching ways of refining techniques for the accurate satellite tracking of ash clouds. These, he said, are being improved, as are the predictive algorithms for working out how much ash has been ejected into the atmosphere, how much has fallen out of it, and where wind patterns will take it. AVOID, he said, can play a crucial role not only in enabling the tactical avoidance of ash concentrations, but also in confirming the density of airborne ash, enabling the evidence to be used to refine further the algorithms used in prediction, and to build confidence in the tracking and measuring systems deployed in space and on the ground.
Davies wants to see AVOID systems fitted on about 100 aircraft throughout Europe, creating a permanent monitoring system using information from airliners while they are in regular service. At least 20 of these will be EasyJet Airbus A320-family aircraft. Airbus is joining EasyJet and Nicarnica in the AVOID trials, and will carry out the high level atmospheric tests.
Another partner in the AVOID trials is Düsseldorf University's Department of Environmental Measurement Techniques. It has been operating its piston-engined Flight Design CT ultralight aircraft fitted with an AVOID pod (see picture) and sensors for measuring other volcanic products like sulphur dioxide. It has been operating for the last two weeks out of a small strip near Etna, deliberately flying near and even within ash plumes near the mountain, and also near Stromboli, another active volcano in the Mediterranean north of Sicily.
This aircraft was deployed to Iceland during the Mount Grimsvötn eruption in May. The university says it will continue to deploy the aircraft wherever in the world useful research can be performed.